Contents

March 2014

Arsinoitherium was an embrithopod from the Eocene. It is significant for having two horns on its head.

Despite its size and aggressive appearance, the rhino-like Arsinoitherium was actually a gentle giant. It lived in the North African coastal mangrove swamps, where it would have spent most of its time wallowing in the water.

Arsinoitherium would emerge on to land only for brief periods of time because its hind legs were permanently bent and pointed outwards, which was ideal for swimming but not so good for walking. Its awkward gait has been confirmed by the discovery of its fossilized footprints in Egypt. It is thought that Arsinoitherium would have ventured on to land to mate or to move to new feeding areas. It had no natural predators on land or in the sea.

Although Arsinoitherium was vegetarian, its complex means of chewing allowed it to eat only certain types of fruit and leaf. It must therefore have spent much of its time searching for suitable quantities of food in order to maintain its large bulk.

The most obvious feature of Arsinoitherium is its giant double horn, which was larger in the females than the males. Given that it was hollow, and that both sexes had excellent hearing, it is possible that the male used it to create a loud mating call. The males may also have used their horns in mating battles, locking them with a rival and twisting until their opponent surrendered.

April 2014

Liopleurodon was a very large pliosaur from the Jurassic. It was the largest predator to ever live.

Liopleurodon was a giant marine reptile which was part of a group of reptiles called the pliosaurs. This group was part of the plesiosaur group. This animal possessed all the key features of pliosaurs such as four, powerful flippers, a long, narrow snout and needle-sharp teeth.

Most Liopleurodon are black with a white underbelly and spots, like a modern great white shark. This was probably used as camouflage. However, some are green with a white underbelly and no spots at all.

Liopleurodon was a gigantic predator, with the largest specimens reaching 25 metres in length. Along with its extraordinary length, it weighed 150 tonnes. It used its four powerful flippers to propel its heavy bulk through the water silently.

The skull of Liopleurodon was the typical shape of pliosaur head. It was long and heavy and was attached by a strong albeit short neck. Its jaws contained lots of needle-sharp, interlocking teeth; perfect for killing prey quickly and efficiently. Its skull and jawbones were specially designed to withstand the bite force generated by its jaws. Being the largest predator in the late Jurassic seas, animals like marine crocodilians, giant fish, plesiosaurs, ichthyosaurs and even other pliosaurs were included on Liopleurodon's menu.

Most marine reptiles had to close its nostrils whilst underwater; not Liopleurodon. This animal had evolved a nose that was able to smell underwater without inhaling water. This adaptation allowed Liopleurodon to pick up the scent of blood from miles away and, like modern sharks, would follow the trail until they found the animal they were pursuing. The pliosaur would then accelerate towards its prey and the victim would be almost instantly killed by the attacker.